Add missing dependencies

[incognitojam]

• Update lockfile format to version 2 (this is a side effect of running npm install with npm > 7) https://docs.npmjs.com/cli/v8/configuring-npm/package-lock-json#lockfileversion
• Add "missing" dependencies to package.json When I ran npm test, node couldn't find the can-message even though it's a dependency of pandajs. I guess npm has changed and dependencies of dependencies aren't accessible anymore?
• Update .gitignore